import copy
a=[1,2,3]
b=copy.copy(a)

print("a的id：",id(a))
print("b的id：",id(b))

a.append(4)
print(a)
print(b)


#不可变类型
c=(1,2,3)
d=copy.copy(c)

print("c的id：",id(c))
print("d的id：",id(d))

